Pneumatically-operated hoist



June 13, 1967 E. R. POWELL 3,325,148

PNEUMAT I CALL OPERATED HOI ST Filed Dec. 27, 1965 5 Sheets-Sheet 1 INVENTOR. [064)? A? Pan/44 47 TORA/EKS' June 1967 E. R. POWELLPNEUMATIC-ALLY-OPERATED HOIST a Sheets-Sheet? Filed Dec. 2'7, 1965flllllqlllw TN UUT i June 13, 1967 om 3,325,148

PNEUMATICALLY-OPERATED HOIST Filed Dec. 27, 1965 5 Sheets-Sheet Big-iINVENTOR. [paw Q Pom/44 United States Patent 3,325,148PNEUMATICALLY-OPERATED HOIST Edgar R. Powell, 7358 St. Auburn Drive,

Birmingham, Mich. 48010 Filed Dec. 27, 1965, Ser. No. 516,620 7 Claims.(Q1. 254186) This invention relates to a pneumatically-operated hoistand particularly to such a hoist which enables a load car ried therebyto be more easily manipulated and positioned.

Many types of hoists are known in the art, most of which are drivenelectrically. Hoists heretofore known generally have had one commondisadvantage. When the load must be positioned accurately for aparticular use, considerable manipulation of the controls often isrequired to cause the hoist to move the load to the exact position.Particularly if the momentum of the hoist drive is such as to tend tomove the load slightly beyond the intended point when the controls aremanipulated, exact positioning is often difiicult and time consuming. Itis also diflicult with previous hoists to set a delicate load gently ona surface to avoid damage such as denting, scratching, breaking, etc.Particularly if the momentum of the drive tends to cause the load tomove beyond the desired position, the setting of the load on the surfacemay be excessively hard with damage resulting.

The present invention relates to a pneumatically-operated hoist which iscapable of raising and lowering loads with considerable facility andspeed and, in addition, can enable the operator to manually move theload to a precise position once it is moved to an approximate positionby the hoist. Thus, for example, where a load must be accurately alignedwith a stationary object, the load can be brought to the approximateposition by means of the hoist controls, after which the load can simplybe handled by the operator and moved upwardly or downwardly slightly, asrequired, to the position in which it is in the proper alignment. Also,when moving a delicate load down to a surface, for example, the load canbe brought down to a position near the surface, perhaps an inch or a fewinches therefrom, and then the load gently pushed down onto the surfaceby the operator, with the controls of the hoist then manipulated tolower the hoist hook further to release the hook from the load.

The new hoist has other advantages, including having few moving partsand requiring little maintenance. The hoist is capable of moving loadsat high speed and the speed can be easily varied. The hoist also can betailored to the requirements of any particular application with aminimum amount of adjustments and modifications.

It is, therefore, a principal object of the, invention to provide ahoist capable of moving a load to a position and then enabling anoperator to further manipulate the load by hand to a desired position.

Another object of the invention is to provide a pneumatically-operatedhoist capable of operating at controlled high speeds.

Still another object of the invention is to provide apneumatically-operated hoist which can be used for a variety ofapplications with a minimum amount of adjustments and modifications.

Other objects and advantages of the invention will be apparent from thefollowing detailed description of a preferred embodiment thereof,reference being made to the accompanying drawings, in which: FIG. 1 is aview in perspective of a pneumaticallyoperated hoist embodying theinvention, shown supported from an overhead rail, and in turn supportinga specific load by means of a particular supporting hook;

3,325,148 Patented June '13, 1967 FIG. 2 is a somewhat schematic view inlongitudinal cross section taken through the hoist and showing a drumand a piston in one position;

FIG. 3 is a view similar to FIG. 2 but showing the drum and piston inelevation and in another position;

FIG. 4 is a view in perspective of a flow control device used with thehoist of FIGS. 1-3;

FIG. 5 is a view in transverse cross section taken along the line 5-5 ofFIG. 4;

FIG. 6 is a view in transverse the line 6--6 of FIG. 4;

FIG. 7 is a rear view in elevation of a body of a hand controller forthe hoist;

FIG. 8 is a view in a longitudinal cross section taken along the line 88of FIG. 7 and also showing controller components;

FIG. 9 is a view in cross section similar to FIG. 8 and taken along theline 9-9 of FIG. 7;

FIG. 10 is an enlarged view in section of one valve used with thecontroller of FIGS. 79; and

FIG. 11 is an enlarged view in section of another valve used with thecontroller of FIG. 7.

Referring to the drawings, and more particularly to FIG. 1, apneumatically-operated hoist embodying the invention is indicated at 20and is supported from an overhead support or beam 22 by a hoist trolley24. The trolley 24 preferably is of the type discussed in more detail inmy co-pending application Ser. No. 389,143, now United States Patent No.3,261,477. The hoist 20' has a lifting cable 26 extending downwardlytherefrom and has a separate control line assembly indicated at 28terminating in a hand-operated hoist controller 30 located at aconvenient height, preferably around waist level or somewhat thereabove,of the hoist operator.

To illustrate the invention more specifically, the cable 26 is shownconnected to a particular load hook 32 of generally C-shapeconfiguration. The hook 32 includes an arm 34 and supporting cylinder 36which extends into a hollow core of a large roll 38 of paper used inprinting, for example. The hook is designed so that the cable 26 isapproximately over the center of the roll 38 when the supportingcylinder 36 is inserted fully into the core. However, the cylinder 36does not extend completely through the core but terminates short of theopposite end. In this manner, the roll 38 can be moved onto a suitablespindle of a press or the like when aligned therewith.

With hoists heretofore known, the roll 38 had to be raised or lowered bymeans of the hoist and the controller 30 until the core of the roll wasaligned exactly with the spindle. This often was time consuming anddifficult, particularly with the usual hoist in which the momentum ofthe drive tended to carry the cable slightly beyond the desired positionwhen the drive was shut off. Consequently, the manipulation of the loadwas slow, even though the hoist was controlled by an experiencedoperator.

With the new hoist 20, as will be discussed fully subsequently, afterthe supporting hook 32 is engaged with the roll 38, the roll is pickedup by manipulation of the hoist controller 30 and raised or lowered toan approximate position relative to the spindle on which the roll isreceived. The exact positioning of the roll in alignment with thespindle is then accomplished by the operator who simply pushes upwardlyor downwardly slightly on the roll to move it the distance desired untilaligned. By Way of example, the roll can be moved within six inches ofthe spindle and the final manipulation then accomplished by theoperator. The extent of manipulation possible in the positioning of theload depends on a number of factors, such as the size of the hoist, thepneumatic pressure involved, and the weight of the load.

cross section taken along If the load is fragile and is to be set on asurface, the controller 31) can be manipulated to move the load within afew inches, for example of the surface. The load is then pusheddownwardly onto the surface bythe operator through light pressure on theload, at which time the controller 38 is manipulated to lower the hoistcable further and enable the load hook to be disengaged. Hence, there islittle possibility of the operator causing the hoist to be moved too farso that the load sharply contacts the surface and causes damage.

Referring'to FIGS. 2 and 3, the hoist 20 includes a housing 40 havingend walls 42 and 44. A ball screw 46 extends longitudinally through thehousing 40 and is fastened at each end centrally to the end walls 42 and44. A ball screw assembly 48 is mounted on the ball screw 46 and moveslongitudinally in the housing 48 when turned relative to the ball screw.Ball screw assemblies of this nature are known in the art and will notbe discussed in detail. A cable drum 50 is mounted on the ball screwassembly 48 and moves therewith both rotatably and longitudinallyrelative to the screw 46. The drum 50 has a shallow helical groove 52which receives the cable 26 when the load is raised and the cable iswound on the drum. One end of the cable is suitable aflixed to the drumat one end of the helical groove.

A thrust bearing 54 is located adjacent the drum t) and bears against ahub portion 56 of the drum. The hearing 54 is mounted on an extension 58of the drum and is arranged to bear against a piston 60. The piston 68has a peripheral seal 62 which engages and slides on the inner surfaceof the housing 40 in gas-tight relationship. In this manner, the secondend wall 44, the right hand portion of the housing 40, and the piston 68form a power or gas chamber to receive gas for operating the hoist. Asuitable O-ring seal 64 is held by the piston 60 and is in slidable butsealing contact with a sleeve 66 mounted over the right end of the ballscrew 46.

When gas is supplied to the power chamber, air usually being used, andis under sufficient pressure, the piston 60 is moved toward the leftand, through the thrust bearing 54, forces the drum 50 and the ballscrew assembly 48 in the same direction. During this movement, the ballscrew assembly 48 is caused to rotate the drum in a manner to raise thecable 26 and the load. The drum and ball screw assembly in the positionof FIG. 2 support the load in the raised position.

Air is supplied to and exhausted from the chamber through an inletopening 68 in the second end wall 44. The rate of air flow is controlledby a flow control device 70 which, in this instance, is mounted directlyon the end wall 44. Air is supplied to the device 70 from a suitablesource through a line 72 connected to an inlet passage 74 (FIGS. 4 and5). The passage 74 communicates with an outlet passage 76 connected to afirst flexible control line 78 for the hoist controller 30. Air flowfrom the line 72 to the line 78 is controlled by a needle valve 80cooperating with a seat 82 and adjustable by means of a knob 84.

Air from the hoist controller 30 is supplied through a line 86 to aninlet passage 88 and, hence, through an outlet passage 90 to the inletopening 68 in the second end wall 44-. Flow through these passages 88and 90 is controlled by a needle valve 92 cooperating with a valve seat94 and adjustable through a knob 96.

Referring now more particularly to FIGS. 79, the hoist controller 30includes a main body 100 which receives the lines 78 and 86 and isconnected to the housing 40 through a supporting cable 102 (FIG. 1) anda ring 104. A suitable handle 106 extends from the rear of the body 100and a support 108 extends below the body 100.

A check valve 110 is located in the line 78 to enable flow from the flowcontrol device 70 to the hoist controller 30, but not in the oppositedirection. This prevents air in the power chamber from exhausting backthrough the line 78 in the event of failure of the air supply source.

The body has an inlet passage 112 communicating with the line 78 andwith a lower inlet chamber 114. The inlet air flows past a valve 116,when opened, and into a first upper chamber 118. From here, the airflows through a transverse passage to a second lower chamber 122 and toan outlet passage 124. The air then flows through the second flexibleline 86 to the How control device 70 and into the hoist power chamber.When the air builds to a suflicient pressure, it raises the load bymoving the piston to the left, as shown in FIG. 2, until the valve 116is again closed to stop the flow. The valve 116 is operated by anL-shaped lever 126 which is pivotally connected to an upper front cornerof the body 180 by a pin 128.

If the valve 116 is closed and the load is in a given position, it canthen be lowered by opening a second control valve 130 which enables airin the hoist chamber to flow back through the line 86 and the passage124 and into a second upper chamber 132, from which the air is vented orexhausted through vent ports 134. As the air pressure in the hoistchamber thereby decreases, the load will lower as the piston is urgedback toward the right under the force of the load which tends to turnthe cable drum 50 and the ball screw assembly 48 in a manner such as tomove the piston toward the right. The exhaust valve 130 is operated byanother L-shaped lever 136 which also is pivoted at the upper frontcorner of the body by the pin 128.

The supply and exhaust valves 116 and 130 are preferably especiallyconstructed to obtain particular control characteristics. As shown inFIG. 10, the supply valve 116 includes a valve body 138 forming achamber 140 having outlet ports 142. A lower opening 144 of the chamberis normally sealed off by a gasket 146 which also seats against ashoulder 148 between the lower and upper chambers 114 and 118 of thecontrol body 100. A valve stem 150 extends through the valve body 138and below the gasket 146 to a flange 152. A thick valve stem portion 154immediately above the flange 152 is only slightly smaller than a centralopening 156 in the gasket 146. An upper thin portion 158 of the stern158, however, is of much smaller diameter than the central opening 156.

When the valve stem 150 is pushed downwardly against the force of areturn spring by pressure on the L- shaped lever 126, the flange 152moves away from the gasket 146 enabling a small amount of air to flowbetween the large portion 154 of the stern 150 and the central opening156 of the gasket 146. This enables the air to enter the hoist chamberslowly and thereby enables the load to be raised slowly, so that itsmovement can be closely controlled. If the lever 126 is depressedfurther, however, so that the thin portion 158 of the stern 150 extendsthrough the central opening 156, the air flow is much greater with thespeed at which the load is raised much faster. This enables the load tobe raised rapidly, when desired, simply by the operator exerting greaterpressure on the lever 126. The air passing through the central opening156, of course, flows into the chamber 140 of the valve body 138 and outthe ports 142 from which it flows to the transverse passage 120.

The exhaust valve .130 includes a valve body 160 forming a chamber 162with outlet ports 164. A lower central opening 166 of the valve body 160is closed off by a gasket 168 which seats on a shoulder 170 between thelower and upper chambers 122 and 1'32. A valve stem 172 also has a lowerflange 174 but has a thin stern portion 176 immediately thereabove whichextends through a central opening 178 in the gasket 168 when thestem 172is depressed by the lever 136. This enables the air from the powerchamber to be exhausted at a substantially fixed rate controlled by theneedle valve 92 of the flow control device 70. The stem 172 is urgedupwardly by a spring 180 in the same manner as the stem 150.

Regardless of the position of the load, it can be raised or loweredmanually by the operator, simply by lifting upwardly slightly or pushingdownwardly slightly on the load. While the extent to which the load canbe so moved and the pressure required will vary with such factors as thesize of the hoist, the pressures used, and the weight of the load, somemanual movement is always possible and this is sufiicient in practicallyall instances to enable the operator to easily manipulate the load froman approximate position to a predetermined position. In a typicalexample, air pressure can be supplied to the flow control device 70 andto the hoist chamber at a pressure of ninety pounds. The load, andspecifically the roll 38 of paper, can weigh sixty pounds. When the loadis to be raised and lowered over a total distance of six feet, it can beeasily hand manipulated from any approximate position a distance sixinches above or below that position to a predetermined position.Further, if the load is delicate and must be placed carefully on asurface, the load can be lowered to a point slightly above the surfaceby decreasing the pressure in the power chamber by opening the valve 130through the lever 136. At that point, the load is pushed gently againstthe surface by the operator and the lever 136 is again depressed to openthe valve and further exhaust the hoist chamber so that the supportinghook can be lowered more so as to be disengaged from the load tocomplete the operation.

Various modifications of the above described embodiment of the inventionwill be apparent to those skilled in the art and it is to be understoodthat such modifications can be made without departing from the scope ofthe invention, if they are within the spirit and the tenor of theaccompanying claims.

I claim:

1. A hoist for raising and lowering loads and for enabling a load to bevertically positioned by an operator after the load is moved to anapproximate position by the hoist, said hoist comprising a housingforming a gas chamber and an inlet communicating with the chamber, apiston in said housing forming an end of said chamber, a cable drum insaid housing movable longitudinally of said housing with said piston,means in said housing rotatably supporting said drum and causing saiddrum to rotate when moved longitudinally; a flow control devicecomprising a body having an inlet passage for a supply of gas, an outletpassage, a gas passage communicating with said gas inlet of saidhousing, a needle valve associated with said inlet passage to controlthe supply of gas therefrom, a second needle valve associated with saidgas passage to control the flow of gas therethrough, a first flexiblegas line communicating with said outlet passage, a second flexible gasline communicating with said gas passage; a hand controller including amain body, a handle attached to said main body, said man body having aninlet connection to receive said first gas line, a second connection toreceive said second gas line, a transverse passage connecting said firstand said second connections, a first valve arranged to control the flowthrough said transverse passage, a lever pivotally connected to saidbody for operating said first valve by hand, a vent in said main bodycommunicating with said second gas line downstream of said first valve,a second valve in said body to control the flow of gas from said secondline to said vent, a second lever connected to said body for operatingsaid second valve, and a check valve in said first gas line to preventflow therethrou-gh from said main body to said flow control device.

2. A hoist for raising and lowering loads and for en abling a load to bemanipulated directly by an operator after the load is moved to anapproximate position by the hoist, said hoist comprising a housingforming a gas chamber and an inlet communicating with the chamber, apiston in said housing forming an end of said chamber, a cable drum insaid housing movable longitudinally of said housing with said piston,means in said housing rotatably supporting said drum and causing saiddrum to rotate when moved longitudinally, a source of gas, a flowcontrol device for regulating rate of flow of gas to said chamber fromsaid source, a hand controller including a body, said body having aninlet connection, and a second connection, a first flexible gas linecommunicating with said inlet connection and said flow control device tosupply gas from said device to said hand controller, a second flexiblegas line communicating with said second connection and said flow controldevice to supply gas from said controller to said device, saidcontroller having a first valve in said body arranged to control flow ofgas from said first line to said second line, a vent in said bodydisposed to communicate with said second gas line, and a second valve insaid body arranged to control flow of gas back from said second line tosaid vent.

3. A hoist according to claim 2 wherein said flow control devicecomprises a body having an inlet passage connected with the source ofgas, an outlet passage connected with said first flexible gas line,valve means associated with said inlet passage and said outlet passagefor regulating the flow of gas therethrough, a second inlet passageconnected with said second flexible gas line, a second outlet passagecommunicating with said housing inlet, and second valve means associatedwith said second inlet passage and said second outlet passage forcontrolling the flow of gas therethrough.

4. A hoist according to claim 2 wherein said hand controller is furthercharacterized by a transverse passage connected between said inletconnection and said second connection downstream of said first valve andindependent of said second valve.

5. A hoist according to claim 4 characterized by said second valve insaid controller being a poppet valve including means forming an openingof predetermined diameter between said second flexible gas line and saidvent, and a stem having an end flange adapted to close said opening whensaid stem is in one position, said stem having a thin portionsubstantially smaller than said opening adapted to be disposed in saidopening when said valve stem is in a second position to enable asubstantially unrestricted flow of gas therethrough.

6. A hoist according to claim-4 wherein said first valve includes meansforming an opening between said first flexible gas line and saidtransverse passage, and a stem extending through said opening and havingan end flange adapted to close said opening when said stem is in oneposition, said stem having a thick portion slightly smaller than saidopening above said flange and a thin portion substantially smaller indiameter than said opening beyond said thick portion, whereby said stemenables relatively small flow of gas through said opening when in asecond position with the thick portion in said opening and enablesgreater flow of gas through said opening when in a third position withsaid thin portion in said opening.

7. A hoist for raising and lowering loads and for enabling a load to bemanipulated directly by an operator after the load is moved to anapproximate position by the hoist, said hoist comprising a housingforming a gas chamber and an inlet communicating with said chamber, apiston in said housing forming an end of said chamber a cable drum insaid housing movable longitudinally of said housing with said piston,means in said housing rotatably supporting said drum and causing saiddrum to rotate when moved longitudinally, a source of gas, a flowcontrol device for regulating rate of flow of gas to said chamber fromsaid source, a hand controller including a body, said body having aninlet connection, and a second connection, a first flexible gas linecommunicating with said inlet connection to supply gas from said sourceto said hand controller, a second flexible gas line communicating withsaid second connection and said flow control device to supply gas fromsaid controller to said device, said controller having a first valve insaid body arranged to control flow of gas from said first line to said.second line, a vent disposed to communicate with said second gas line,and a 7 second valve in said'body arranged to control flow of gas2,500,879 back from said second line to said vent. 2,710,107 2,831,554References Clted 2,932,316 UNITED STATES PATENTS 5 1,606,426 11/1926Justen 137-5962 2,129,511 9/1938 Thompkins et a1 25112 1 2,478,494 8/1949 Martin 254-150 %3 Smallpiece. Powell. Reynolds 254186 Stanton251-121 EVON C. BLUNK, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.

2. A HOIST FOR RAISING AND LOWERING LOADS AND FOR ENABLING A LOAD TO BEMANIPULATED DIRECTLY BY AN OPERATOR AFTER THE LOAD IS MOVED TO ANAPPROXIMATE POSITION BY THE HOIST, SAID HOIST COMPRISING A HOUSINGFORMING A GAS CHAMBER AND AN INLET COMMUNICATING WITH THE CHAMBER, APISTON IN SAID HOUSING FORMING AN END OF SAID CHAMBER, A CABLE DRUM INSAID HOUSING MOVABLE LONGITUDINALLY OF SAID HOUSING WITH SAID PISTON,MEANS IN SAID HOUSING ROTATABLY SUPPORTING SAID DRUM AND CAUSING SAIDDRUM TO ROTATE WHEN MOVED LONGITUDINALLY, A SOURCE OF GAS, A FLOWCONTROL DEVICE FOR REGULATING RATE OF FLOW OF GAS TO SAID CHAMBER FROMSAID SOURCE, A HAND CONTROLLER INCLUDING A BODY, SAID BODY HAVING ANINLET CONNECTION, AND A SECOND CONNECTION, A FIRST FLEXIBLE GAS LINECOMMUNICATING WITH SAID INLET CONNECTION AND SAID FLOW CONTROL DEVICE TOSUPPLY GAS FROM SAID DEVICE TO SAID HAND CONTROLLER, A SECOND FLEXIBLEGAS LINE COMMUNICATING WITH SAID SECOND CONNECTION AND SAID FLOW CONTROLDEVICE TO SUPPLY GAS FROM SAID CONTROLLER TO SAID DEVICE, SAIDCONTROLLER HAVING A FIRST VALVE IN SAID BODY ARRANGED TO CONTROL FLOW OFGAS FROM SAID FIRST LINE TO SAID